The present invention relates to recovery and utilization of heat naturally produced in the course of dairy operations wherein cows are housed and milked in an enclosed barn. More specifically, the invention relates to refrigeration circuits for absorbing heat generated by the body heat and the milk of dairy cattle and giving up the heat to water used in residential heating and/or domestic hot water.
It is a common practice in northern climates to keep dairy cattle housed in a barn essentially continuously during the winter months, aside from relatively brief exercise periods. The body heat generated by the cows raises the temperature within the barn to a level considerably above that of the outside temperature. For example, it is not uncommon for the temperature inside a dairy barn to be 65.degree. F. when the outside temperature is as low as 0.degree. F. without providing any heat to the barn other than that of the cows' body heat.
When milk is to be stored for any significant period of time it is necessary that it be cooled. To this end, milk cooling tanks are provided in a wide variety of models and capacities. In some cases, heat absorbed in the cooling coils is usefully employed in heaters or pre-heaters for water to be used in connection with the dairy operation or for other domestic purposes.
It is a principal object of the present invention to provide a novel heating method and system which recovers and usefully employs body heat given off by cows in an enclosed dairy barn, as well as heat absorbed during cooling of the milk from such cows.
Another object is to provide means for supplementing an existing residential heating system with animal body heat which is not otherwise usefully employed.
A further object is to provide a waste heat utilization system employing two separate refrigeration circuits for absorbing heat from two sources, both associated with a dairy operation.
In a more general sense, the object of the invention is to provide heating methods and systems which recover and utilize in an energy saving manner naturally available heat which is otherwise wasted.
Other objects will in part be obvious and will in part appear hereinafter.